Charged particle sources are used for various surface modification, etching and deposition applications, and are particularly advantageous compared to other methods for providing direct control of particle energy and flux, angle of incidence to the substrate, and isolation of the substrate from the conditions of the reactor used to generate the etching and or depositing species.
In an ion beam source, ions are extracted from the plasma in the source. Since a plasma is quasi-neutral, equal number of electrons need to escape from the plasma, before plasma instabilities are caused. The escape path for the electrons is the beam grid, which is a conducting path for the electrons.
In a non-reactive gas plasma, such as an Argon (Ar+) plasma, the beam grid surface remains conductive, and provides a very reliable escape path for the electrons. However, when reactive gases are used, the beam grid surface can get oxidized, and stop providing an escape path for the electrons. In a Hydrocarbon (CH) precursor based plasma needed for the Tetrahedral Hydrogenated Carbon (Ta—C—H) direct ion beam for diamond-like carbon (DLC) films, as soon as the plasma is created, very low energy CHx+ ions deposit on all exposed surfaces, including the beam grid surface. This creates a thin Carbon coating on all such exposed surfaces in the ion source, and eliminates the escape path for the electrons in the plasma as the ions are extracted from the plasma. Plasma instability is caused as a result, and severe arcing is created, causing source instability, as well as particles within the system.
Therefore, what is needed is a charged particle source that reduces the Carbon coating on the exposed surfaces of the beam grid in the ion source.
Nothing in the prior art provides the benefits attendant with the present invention.
Therefore, it is an object of the present invention to provide an improvement which overcomes the inadequacies of the prior art devices and which is a significant contribution to the advancement of depositing Carbon using a charged particle source.
Another object of the present invention is to provide a charged particle source comprising: a plasma processing chamber; a plasma source having a wall operatively connected to the processing chamber; an ion extraction grid operatively connected to the processing chamber; a conducting plate within the plasma source and adjacent to the wall of the plasma source, the conducting plate having a surface having a plurality of grooves, the plurality of grooves facing the wall of the plasma source; a substrate on a substrate support disposed in an interior portion of the processing chamber; and a gas supply operatively connected to the processing chamber.
Yet another object of the present invention is to provide a charged particle source comprising: a plasma processing chamber; a plasma source having a wall operatively connected to the processing chamber; a plurality of ion extraction grids operatively connected to the processing chamber; a conducting plate within the plasma source at a distance from the wall of the plasma source, the conducting plate having a plurality of grooves, the plurality of grooves facing the wall of the plasma source; a substrate on a substrate support disposed in an interior portion of the processing chamber; and a gas supply operatively connected to the processing chamber.
Still yet another object of the present invention is to provide a charged particle source comprising: a plasma processing chamber; a plasma source having a wall operatively connected to the processing chamber; a plurality of ion extraction grids operatively connected to the processing chamber; a conducting plate within the plasma source at an adjustable distance from the wall of the plasma source, the conducting plate having a plurality of grooves, the plurality of grooves facing the wall of the plasma source, the conducting plate being opposite the plurality of ion extraction grids; a substrate on a substrate support disposed in an interior portion of the processing chamber; and a gas supply operatively connected to the processing chamber.
The foregoing has outlined some of the pertinent objects of the present invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.